How to use dynamic import in Next JS

Dynamic Import Next JS

In Next.js, importing components and modules is a fundamental aspect of building React applications. Next.js provides a few features and optimizations related to importing, including dynamic import.

Dynamic import is a feature that allows you to load modules or components only when they are needed. This is beneficial for code splitting, where you can split your JavaScript bundle into smaller chunks that are loaded on-demand.

What is Next/Dynamic?

The next/dynamic module is used to dynamically import a component or module, allowing for code splitting. Code splitting is a technique that enables a web application to load only the necessary code for the current page, improving performance by reducing the initial bundle size.

Getting Started

To get started with next/dynamic, you need to set up your Next.js application. You can create a new Next.js application using the create-next-app command or by cloning the Next.js starter template from GitHub.

Once you have set up your Next.js application, you can start using next/dynamic to load your components dynamically. To do this, you need to import the dynamic function from the next/dynamic module. You can then use this function to create a new dynamic component.

Here’s a basic example of how next/dynamic can be used:

// ExampleComponent.js
const ExampleComponent = () => {
  return <div>This is a dynamically imported component.</div>;
};

export default ExampleComponent;

Now, let’s use next/dynamic to dynamically import ExampleComponent in another file:

// SomePage.js
import dynamic from 'next/dynamic';

const DynamicExampleComponent = dynamic(() => import('../components/ExampleComponent'), {
  loading: () => <p>Loading...</p>,
  ssr: false, // Set to false to disable server-side rendering for this component
});

const SomePage = () => {
  return (
    <div>
      <p>This is a regular component on the page.</p>
      <DynamicExampleComponent />
    </div>
  );
};

export default SomePage;

In this example, DynamicExampleComponent is a dynamically imported version of ExampleComponent. The import('../components/ExampleComponent') statement is wrapped inside the dynamic function. The loading prop is optional and allows you to provide a loading indicator or placeholder while the component is being loaded.

The ssr (server-side rendering) prop is set to false in this example. This means that the component will be loaded only on the client side and won’t be part of the initial server-side rendered content. This can be useful for components that are not needed during the initial render or if they depend on client-side functionality.

What exactly is server-side rendering?

Server-Side Rendering (SSR) in Next.js refers to the ability to generate the initial HTML for a page on the server side, before sending it to the client. This is in contrast to traditional client-side rendering (CSR), where the HTML is generated on the client side using JavaScript. Next.js provides a powerful mechanism for implementing SSR.

Why should we use dynamic import in next JS?

Using dynamic imports in next.js has many benefits :

Code Splitting – Dynamic import allows you to split your code into smaller chunks. This is particularly useful for large applications, as it reduces the initial load time by loading only the necessary code for the current page.

Faster Initial Page Load – By loading only the essential code for the current page, you can significantly improve the initial page load performance. Users will only download the JavaScript code needed for the page they are visiting, resulting in faster loading times.

Reduced Bundle Size – Smaller bundles mean faster downloads, especially on slower networks. Dynamic import helps in optimizing the bundle size by loading code on-demand, reducing the initial payload.

Improved User Experience – Users experience faster page transitions as only the required components are loaded when navigating between pages. This leads to a smoother and more responsive user experience.


FAQs on Dynamic Import

Q1. How does dynamic import contribute to performance improvement?

Dynamic import improves performance by loading only the necessary code when required, reducing the initial bundle size. This asynchronous loading enhances page load times and overall responsiveness.

Q2. Can dynamic import be used for code splitting in Next.js?

Yes, dynamic import is a key mechanism for code splitting in Next.js. It enables developers to divide the application code into smaller, more manageable chunks, optimizing resource distribution and load times.

Q3. In what scenarios is dynamic import particularly beneficial?

Dynamic import is beneficial in scenarios where there are large projects with numerous components and pages. It’s especially useful for optimizing performance, reducing initial bundle size, and improving user interactions.

Q4. Can dynamic import be used for optimizing resource utilization in Next.js?

Yes, dynamic import optimizes resource utilization by loading only the necessary components or modules as users interact with different parts of the application. This efficient loading contributes to a smoother user experience.

Q5. Does dynamic import support other file types besides JavaScript modules?

Yes, dynamic import in Next.js supports loading other file types, such as stylesheets or images, in addition to JavaScript modules. This flexibility allows for a more comprehensive approach to optimizing resource loading.


Final Notes

In summary, dynamic import in Next.js is a powerful feature for optimizing performance by loading code on-demand, reducing bundle sizes, and improving the overall user experience. It’s particularly beneficial in larger applications where code splitting is essential for efficient resource utilization.